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  <title>十进制转换为二进制</title>

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</div><hr /><div id="function.decbin" class="refentry">
   <div class="refnamediv">
    <h1 class="refname">decbin</h1>
    <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">decbin</span> &mdash; <span class="dc-title">十进制转换为二进制</span></p>

   </div>
 <div class="refsect1 description" id="refsect1-function.decbin-description">
  <h3 class="title">说明</h3>
     <div class="methodsynopsis dc-description">
      <span class="type">string</span> <span class="methodname"><strong>decbin</strong></span>
       ( <span class="methodparam"><span class="type">int</span> <code class="parameter">$number</code></span>
      )</div>

    <p class="para rdfs-comment">
     返回一字符串，包含有给定
     <em><code class="parameter">number</code></em> 参数的二进制表示。所能转换的最大数值为十进制的
     4294967295，其结果为 32 个 1 的字符串。
    </p>
   </div>

 <div class="refsect1 parameters" id="refsect1-function.decbin-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<em><code class="parameter">number</code></em></dt>

     <dd>

      <p class="para">
       Decimal value to convert
      </p>

      <table class="doctable table">
       <caption><strong>Range of inputs on 32-bit machines</strong></caption>
       
        <col />
        <col />
        <col />
        <thead>
         <tr>
          <th>positive <em><code class="parameter">number</code></em></th>
          <th>negative <em><code class="parameter">number</code></em></th>
          <th>return value</th>
         </tr>

        </thead>

        <tbody class="tbody">
         <tr>
          <td>0</td>
          <td class="empty">&nbsp;</td>
          <td>0</td>
         </tr>

         <tr>
          <td>1</td>
          <td class="empty">&nbsp;</td>
          <td>1</td>
         </tr>

         <tr>
          <td>2</td>
          <td class="empty">&nbsp;</td>
          <td>10</td>
         </tr>

         <tr>
          <td colspan="3">... normal progression ...</td>
         </tr>

         <tr>
          <td>2147483646</td>
          <td class="empty">&nbsp;</td>
          <td>1111111111111111111111111111110</td>
         </tr>

         <tr>
          <td>2147483647 (largest signed integer)</td>
          <td class="empty">&nbsp;</td>
          <td>1111111111111111111111111111111 (31 1&#039;s)</td>
         </tr>

         <tr>
          <td>2147483648</td>
          <td>-2147483648</td>
          <td>10000000000000000000000000000000</td>
         </tr>

         <tr>
          <td colspan="3">... normal progression ...</td>
         </tr>

         <tr>
          <td>4294967294</td>
          <td>-2</td>
          <td>11111111111111111111111111111110</td>
         </tr>

         <tr>
          <td>4294967295 (largest unsigned integer)</td>
          <td>-1</td>
          <td>11111111111111111111111111111111 (32 1&#039;s)</td>
         </tr>

        </tbody>
       
      </table>


      <table class="doctable table">
       <caption><strong>Range of inputs on 64-bit machines</strong></caption>
       
        <col />
        <col />
        <col />
        <thead>
         <tr>
          <th>positive <em><code class="parameter">number</code></em></th>
          <th>negative <em><code class="parameter">number</code></em></th>
          <th>return value</th>
         </tr>

        </thead>

        <tbody class="tbody">
         <tr>
          <td>0</td>
          <td class="empty">&nbsp;</td>
          <td>0</td>
         </tr>

         <tr>
          <td>1</td>
          <td class="empty">&nbsp;</td>
          <td>1</td>
         </tr>

         <tr>
          <td>2</td>
          <td class="empty">&nbsp;</td>
          <td>10</td>
         </tr>

         <tr>
          <td colspan="3">... normal progression ...</td>
         </tr>

         <tr>
          <td>9223372036854775806</td>
          <td class="empty">&nbsp;</td>
          <td>111111111111111111111111111111111111111111111111111111111111110</td>
         </tr>

         <tr>
          <td>9223372036854775807 (largest signed integer)</td>
          <td class="empty">&nbsp;</td>
          <td>111111111111111111111111111111111111111111111111111111111111111 (63 1&#039;s)</td>
         </tr>

         <tr>
          <td class="empty">&nbsp;</td>
          <td>-9223372036854775808</td>
          <td>1000000000000000000000000000000000000000000000000000000000000000</td>
         </tr>

         <tr>
          <td colspan="3">... normal progression ...</td>
         </tr>

         <tr>
          <td class="empty">&nbsp;</td>
          <td>-2</td>
          <td>1111111111111111111111111111111111111111111111111111111111111110</td>
         </tr>

         <tr>
          <td class="empty">&nbsp;</td>
          <td>-1</td>
          <td>1111111111111111111111111111111111111111111111111111111111111111 (64 1&#039;s)</td>
         </tr>

        </tbody>
       
      </table>


     </dd>

    
   </dl>

  </p>
 </div>

 <div class="refsect1 returnvalues" id="refsect1-function.decbin-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   Binary string representation of <em><code class="parameter">number</code></em>
  </p>
 </div>

 <div class="refsect1 examples" id="refsect1-function.decbin-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-3362">
    <p><strong>Example #1 <span class="function"><strong>decbin()</strong></span> 例子</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">echo&nbsp;</span><span style="color: #0000BB">decbin</span><span style="color: #007700">(</span><span style="color: #0000BB">12</span><span style="color: #007700">)&nbsp;.&nbsp;</span><span style="color: #DD0000">"\n"</span><span style="color: #007700">;<br />echo&nbsp;</span><span style="color: #0000BB">decbin</span><span style="color: #007700">(</span><span style="color: #0000BB">26</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>以上例程会输出：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
1100
11010
</pre></div>
    </div>
   </div>
  </p>
 </div>

 <div class="refsect1 seealso" id="refsect1-function.decbin-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.bindec.html" class="function" rel="rdfs-seeAlso">bindec()</a> - 二进制转换为十进制</span></li>
    <li class="member"><span class="function"><a href="function.decoct.html" class="function" rel="rdfs-seeAlso">decoct()</a> - 十进制转换为八进制</span></li>
    <li class="member"><span class="function"><a href="function.dechex.html" class="function" rel="rdfs-seeAlso">dechex()</a> - 十进制转换为十六进制</span></li>
    <li class="member"><span class="function"><a href="function.base-convert.html" class="function" rel="rdfs-seeAlso">base_convert()</a> - 在任意进制之间转换数字</span></li>
    <li class="member">
     <span class="function"><a href="function.printf.html" class="function" rel="rdfs-seeAlso">printf()</a> - 输出格式化字符串</span>, using <em>%b</em>,
     <em>%032b</em> or <em>%064b</em> as the format
    </li>
    <li class="member">
     <span class="function"><a href="function.sprintf.html" class="function">sprintf()</a></span>, using <em>%b</em>,
     <em>%032b</em> or <em>%064b</em> as the format
    </li>
   </ul>
  </p>
 </div>

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